Odds ratios and 95% confidence intervals for recurrent wheezing in children in the BAMSE case-control study, classified as having recurrent wheezing at 1 year and 2 years of age, respectively, in relation to measured and calculated annual outdoor and indoor NO2 exposure
| Concentration of NO2 (µg/m3) | |||||||||
|---|---|---|---|---|---|---|---|---|---|
| Controls | Cases | <25th centile | 25–50th centile | 51–75th centile | >75th centile | ||||
| OR | OR* | 95%CI | OR* | 95%CI | OR* | 95%CI | |||
| *Adjusted for gender, heredity, maternal age and smoking, any breast feeding, and building age. | |||||||||
| †Indoor NO2 exposure, range within different quartiles: <8.4 µg/m3; 8.4–11.6 µg/m3; 11.7–15.6 µg/m3; and >15.6 µg/m3, respectively. | |||||||||
| ‡Outdoor NO2 exposure, range within different quartiles: <14.8 µg/m3; 14.8–21.3 µg/m3; 21.4–28.4 µg/m3; and >28.4 µg/m3, respectively. | |||||||||
| Indoor exposure† | |||||||||
| Measured data: | |||||||||
| Age 1 year | 176 | 90 | 1 | 0.97 | 0.42 to 2.24 | 1.17 | 0.46 to 2.99 | 1.42 | 0.59 to 3.43 |
| Age 2 year | 154 | 88 | 1 | 0.79 | 0.29 to 2.08 | 0.97 | 0.38 to 2.48 | 1.31 | 0.49 to 3.47 |
| Outdoor exposure‡ | |||||||||
| Measured data: | |||||||||
| Age 1 year | 174 | 89 | 1 | 0.88 | 0.38 to 2.03 | 0.35 | 0.14 to 0.93 | 1.48 | 0.53 to 4.14 |
| Age 2 year | 156 | 79 | 1 | 0.93 | 0.36 to 2.44 | 1.85 | 0.72 to 4.76 | 2.81 | 0.93 to 8.46 |
| Calculated annual average exposure: | |||||||||
| Age 1 year | 174 | 89 | 1 | 1.08 | 0.49 to 2.39 | 0.38 | 0.14 to 1.02 | 1.88 | 0.65 to 5.43 |
| Age 2 year | 156 | 79 | 1 | 0.79 | 0.29 to 2.17 | 1.50 | 0.54 to 4.14 | 2.27 | 0.82 to 6.30 |